0,3

a(n)=a(3n)=a(3n+2)/3; a(3n+2)=0.

Table of n, a(n) for n=0..98.

a(n)=sum{k=0..n, L(C(n,k)/3)*(-1)^k} where L(j/p) is the Legendre symbol of j and p.

Sequence in context: A219551 A200221 A158678 * A065032 A007514 A151671

Adjacent sequences: A117977 A117978 A117979 * A117981 A117982 A117983

easy,nonn

Paul Barry, Apr 06 2006

approved